Full Stack Systems
React, TypeScript, Node.js, REST/GraphQL APIs and modern web architecture — from component systems to service boundaries.
Senior Full Stack / Platform Engineer
Marc Lally
TypeScript · Node.js · React · AWS · Distributed Systems · AI
I design and build reliable production systems across the full stack — from React interfaces and Node.js services to distributed AWS infrastructure, payment systems and AI-powered workflows.
Current focus
Distributed systems + AI Engineering
Cloud-native platforms, serverless architecture, secure payment and identity systems, and production AI workflows — built with the same discipline as any other subsystem.
TypeScript
AWS
AI Workflows
Capability
What I build
Distributed Systems
Event-driven architecture, queues, asynchronous processing, microservices, reliability and observability at scale.
Cloud & Infrastructure
AWS, Lambda, API Gateway, SQS, SNS, DynamoDB, infrastructure automation and serverless architecture.
AI Engineering
AI agents, LLM workflows, tool orchestration, structured outputs, evaluation and production AI integrations.
Payments & Security
Payment infrastructure, Stripe, Adyen, PCI considerations, authentication, IAM, OAuth2, JWT and secure system design.
Profile
Engineering profile
Engineering profile
JavaScript and TypeScript have been central to my career. Node.js and React are my core technologies, and I have significant depth in Python and Rust for services, tooling and AI systems.
I design distributed systems that handle payments and high-throughput traffic — with transaction reliability, idempotency and security designed in from the start. I build serverless platforms on AWS (Lambda, API Gateway, SQS, DynamoDB) and care about failure modes, observability and operational simplicity as much as feature delivery.
Increasingly I apply that discipline to AI. I build agents and LLM workflows the way I build any production system — with evaluation, observability and security designed in, not bolted on.
Leadership
I have led technical delivery across enterprise and startup teams — owning architecture, API contracts, CI/CD, observability and engineering standards, and mentoring engineers through system design and operational maturity.
I translate business requirements into coherent technical direction: clear service boundaries, data ownership and delivery plans that keep teams moving at velocity without compromising platform integrity.
Stack
Technology
TypeScript
Node.js
React
AWS
Distributed Systems
AI
Languages
- TypeScript
- JavaScript
- Python
- Rust
- Go
- PHP
Frontend
- React
- Next.js
- JSX
- Modern browser APIs
- Component architecture
Backend
- Node.js
- REST
- GraphQL
- FastAPI
- Microservices
- Event-driven systems
Cloud / Infrastructure
- AWS
- Lambda
- API Gateway
- SQS
- SNS
- DynamoDB
- Docker
- Linux
- CI/CD
AI
- LLM applications
- AI agents
- Agent SDK
- LangChain
- LangSmith
- Pydantic AI
- Structured outputs
- Tool orchestration
- Evaluation
- AI workflows
Data
- PostgreSQL
- MongoDB
- Redis
- Elasticsearch
- DynamoDB
- GraphQL
Security / Payments
- OAuth2
- JWT
- IAM
- SSO
- PCI DSS
- Stripe
- Adyen
- Encryption
- Threat modelling
Experience
PayStacks
February 2026 - Present
CTO & Founder
Contract
React.js
TypeScript
Node.js
AWS
PostgreSQL/MongoDB
Redis
Next.js
OAuth/HECE/HMAC
Rust (API)
TDD
Agentic/OpenAI API, Gradio
AI Workflows/Agents
- Founder and technical lead for an enterprise-grade payment services gateway: a high-security REST API in Rust with SDKs across every major language, runtime and mobile platform, plus a full sandbox for unlimited integration testing.
- Designed the platform around transaction integrity — Hydra Ephemeral Channel Encryption derives a per-request AES-256-GCM key via HKDF-SHA256, bound with HMAC-SHA256, tying every API call to its exact request path and timestamp.
- Built a hybrid AI/ML model that scores every transaction in real time, with a review queue, threshold controls and online feedback learning to reduce fraud across multiple risk dimensions.
- Own the full-stack product: Next.js/React frontend with animated dashboards, a workbench and extensive audit and security logs — covered by comprehensive testing with viTest and Jest, and Playwright for E2E.
- Built and deployed production agents for social integrations, customer support, sales and security, including agents that mock the transactional process to improve and develop user integrations.
- Developed agentic workflows for automated technical design reviews, leveraging LLMs for context-aware code reasoning and architectural consistency checks, with Pydantic AI, Agents SDK, LangChain, LangSmith, Gradio and FastAPI.
Cyber & Specialist Ops, Virgin Atlantic
February 2025 - January 2026
Senior Fullstack Engineer
Contract
Node.js
TypeScript
Serverless
AWS
PostgreSQl
OAuth 2.0
JWT
AI Workflows
AI Agents
- Architected AI-powered security workflows using vector embeddings to surface anomalies in high-throughput identity logs, improving threat detection speed.
- Delivered high-throughput Node.js microservices on AWS Lambda and DynamoDB, implementing fine-grained IAM policies for secure deployment. Optimized AWS concurrency and execution-context reuse to sustain latency under JWT-authenticated traffic volumes.
- TDD with Jest and Supertest, raising code coverage and cutting production regressions. Established contract testing with Pact to stabilize distributed service boundaries.
- Hardened the security posture by integrating threat modeling and automated dependency scanning into CI/CD pipelines, building secure-by-default patterns for OAuth 2.0 and JWT identity flows.
- Aggressive profiling with AWS X-Ray and performance tuning of DynamoDB GSI/LSI patterns. Scaled platform throughput via intelligent request batching and SQS-driven async processing.
- Implemented comprehensive observability with structured logging, distributed tracing and custom metrics (New Relic) for rapid incident resolution, and built internal tooling integrations in Node/AWS.
- Built AI agents using Pydantic AI, Agents SDK, LangChain, LangSmith, Gradio and other tools to optimize and control workflows and run DevOps tasks, alongside Lambda functions and state machine workflows.
Codeium
March 2023 - December 2024
Senior Full Stack Engineer | Tech Lead
Contract
React.js
TypeScript
Node.js
AWS
PostgreSQL/MongoDB
Serverless
OAuth/JWT
TDD
AI Workflows
AI Agents
- Full-stack development of enterprise-grade AI coding assistants, optimizing real-time inference delivery and high-throughput vector indexing workflows.
- Architected scalable React/TypeScript interfaces for complex developer workflows, including VS Code and JetBrains IDE integrations.
- Designed and implemented zero-trust authentication and authorization patterns for multi-tenant enterprise deployments.
- Optimized frontend performance and state management (Redux/Zustand), reducing client-side latency for large repositories.
- Established rigorous E2E testing patterns (Playwright/Cypress/Jest) and CI/CD automation, ensuring stability across diverse deployment environments.
- Developed agentic workflows for automated technical design reviews, leveraging LLMs for context-aware code reasoning and architectural consistency checks, with Pydantic AI, Agents SDK, LangChain, LangSmith, Gradio and FastAPI.
- Designed and built scalable frontend interfaces using Next.js, React and various frontend javascript frameworks and libraries to support extension of functions or new features.
Shell Global Energy
July 2022 - February 2023
Senior Full Stack Engineer
Contract
Node.js
React.js
Serverless
TypeScript
AWS
GraphQL/DynamoDB
OAuth/JWT
Payments
- Engineered a horizontally-scalable GraphQL layer (Apollo Server) on Node.js/Lambda. Optimized data fetching for high-throughput daily transactions through Dataloader batching and Redis-based caching strategies.
- Developed robust payment pipelines with Stripe and Adyen, implementing PCI DSS Level 1 compliance, idempotency keys, and sophisticated webhook retry policies to ensure transaction integrity. JWT and OAuth.
- Implemented fault-tolerant architectural patterns including circuit breakers, bulkheading, and dead-letter queues to maintain platform stability under extreme load using AWS Lambda and SQS, SNS and S3.
- Implemented comprehensive monitoring with AWS CloudWatch, X-Ray, and custom dashboards; configured intelligent alerting enabling rapid incident resolution and proactive issue detection.
- Mentored 6+ engineers on distributed systems, payment processing, and system design; conducted 40+ technical interviews.
- Improved deployment velocity enabling 5+ releases daily through CI/CD automation and feature flags; conducted disaster recovery drills. Ensured full system replication and failure strategies with Terraform and CloudFormation. AWS SQS and SNS with Lambda were used to replace legacy services.
- Design and build new frontend interface UI for Shell internal tooling/order and management system using Next.js, React.js, TypeScript and various frontend libraries to support extension of functions or new features.
Studio Rotate
June 2021 - July 2022
Senior Full Stack Engineer | Tech Lead
Node.js
Next.js
Vue.js
React.js
AWS
Serverless
OAuth/JWT
Payments
- Directed technical delivery for high-visibility Next.js/Vue.js applications. Defined clean API contracts and schema governance to support extensive user sessions without architectural sprawl. Built Serverless API in Node to support various frontends.
- Built and managed infrastructure using Terraform and AWS, deploying Node.js/Serverless backends with automated CI/CD pipelines via GitHub Actions.
- Elevated engineering maturity by introducing ESLint/Prettier standards, trunk-based development, and peer code review workflows. Mentored senior engineers on system design and performance profiling.
- Implemented deep observability and alerting; analyzed performance metrics to identify and eliminate bottlenecks, resulting in a significant improvement in system throughput.
- Resolved critical dev bugs and issuess through systematic root cause analysis, establishing post-mortem practices that converted failures into long-term system improvements.
- Designed and built backend Serverless API to support builds taking place for Chillys and Big Green Egg. Built frontends in Next.js, Vue.js and React.js
Sainsburys Digital
December 2020 - June 2021
Senior Backend Engineer
Contract
GraphQL
Next.js
Node.js
TypeScript
TDD
DV360
- Modernized legacy Node.js/TypeScript services by refactoring to a modular architecture and patching critical vulnerabilities. Integrated Google DV360 API via a Next.js middleware layer, processing massive ad impression datasets.
- Optimized the critical rendering path; reduced React bundle sizes and slashed LCP through aggressive code-splitting and asset optimization.
- Hardened data security by implementing end-to-end encryption and field-level access controls, ensuring strict compliance without slowing down feature delivery using encryption libraries and AWS KMS.
- Architected modular, decoupled components and reusable utilities that made the codebase more efficient and easier to maintain, enabling faster development cycles and reducing technical debt.
- Collaborated on GraphQL schema design and cross-team API contracts, leading architecture walkthroughs to ensure technical alignment. Designed Architectural patterns and built them.
- Advanced PostgreSQL performance through strategic indexing, connection pooling (PgBouncer), and schema normalization, resulting in a significant gain in query efficiency under concurrent load.
KFC Europe
December 2019- November 2020
Senior Fullstack Engineer | Tech Lead
Node.js
Serverless
AWS
OAuth/JWT
Payments
POS
PostgreSQL
- Orchestrated integrations between web ordering, POS (NCR/MICROS), and loyalty platforms. Established strict API boundaries and contract testing (Pact) to prevent integration drift across microservices.
- Designed multi-tenant AWS Lambda services secured via OAuth 2.0 and JWT, ensuring PCI DSS Level 1 compliance for high-availability fast-food infrastructure.
- Optimized PostgreSQL and DynamoDB schema designs to meet sub-50ms p95 latency targets. Implemented multi-layer caching (Redis/CloudFront) to achieve performance gains.
- Coordinated technical delivery across global teams, enabling a high-release-velocity environment (50+ monthly features) with a heavy focus on stability.
- Mentored 6 engineers through the complexities of distributed systems and payment processing; served as a key technical interviewer.
- Aggressively tuned Lambda resource allocation and cold starts, cutting execution time and infrastructure burn. Architect and build AWS Lambda infrastructure to support the web ordering system and various internal tools using Terraform and CloudFormation. Build Serverless functionality using AWS SQS, SNS and Lambda to replace legacy services and ensure high availability and scalability.
- Design and build modern frontends using Next.js, React.js, for advertising and data collection purposes. Use frontend libraries and frameworks to support extension of functions or new features.
Preqin
February 2019 - November 2019
Senior Frontend Engineer
Contract
React.js
Node.js
Vanilla JS
ElasticSearch
TypeScript
TDD
- Directed frontend architecture for a high-traffic financial platform. Combined React, TypeScript, and Elasticsearch to deliver high-performance search and complex data visualization for institutional investors.
- Authored technical specifications and designs, ensuring architectural decisions aligned with accessibility and performance-first design principles. Provide fast and accurate frontends using React.js, Next.js and various frontend libraries and frameworks to support extension of functions or new features.
- Reduced bundle sizes and significantly improved Core Web Vitals through custom Webpack/Vite configurations and code-splitting strategies.
- Implemented exhaustive test suites using Jest and React Testing Library, achieving high coverage across the critical paths of global financial data flows.
- Mentored junior and mid-level engineers on React patterns, TypeScript, and accessibility, building technical capacity through regular pair programming and code reviews.
- Optimized Elasticsearch query patterns and mapping, reducing search latency across massive financial taxonomies.
MelodyVR
January 2018 - December 2018
Senior Front End Engineer
Contract
React
Node.js
TypeScript
AWS
CMS
- Built a custom React-based CMS on Node.js/Serverless, enabling content teams to orchestrate and distribute VR assets across cross-platform channels with zero downtime.
- Designed a scalable, component-driven UI architecture using Storybook and design tokens, which accelerated iterative feature delivery.
- Managed resilient data pipelines handling high-frequency content updates, ensuring schema stability and zero-downtime deployments.
- Architected CI/CD pipelines using GitHub Actions and Terraform (IaC), slashing deployment cycles from hours to minutes and enabling 16x faster shipping frequency.
- Optimized asset delivery and page performance, cutting load times through aggressive code-splitting and caching strategies.
- Established a rigorous testing culture using Jest and Supertest, achieving better coverage and catching the vast majority of regressions in CI.
Big Clever Learning
April 2017 - November 2017
Senior Back End Engineer
Contract
Node.js
Koa
Swagger
PostgreSQL
MongoDB
Docker
Payments
- Architected a decoupled microservices platform using Node.js and Koa. Defined service boundaries via OpenAPI/Swagger 3.0 to ensure strict contract enforcement.
- Managed polyglot persistence across PostgreSQL, MongoDB, and Redis; delivers high availability and sub-50ms latency for a large user base.
- Integrated Stripe for high-volume billing, maintaining PCI compliance while managing transactions with robust idempotency and error handling.
- Pioneered contract and automated testing suites, ensuring stability across critical financial and counseling data flows.
- Containerized the platform with Docker and modernized infrastructure via Terraform, significantly reducing deployment overhead and improving environment consistency.
- Identified and resolved systemic latency issues, dropping execution times while optimizing cloud infrastructure costs.
FutureBrand
October 2016 - March 2017
Senior Back End Engineer
Contract
PHP
OAuth2
SAML
Craft CMS
MySQL
jQuery
- Spearheaded the integration of OAuth 2.0 and SAML 2.0, enabling secure SSO across diverse enterprise ecosystems with robust token management and key rotation in PHP.
- Developed 20+ custom plugins for Craft CMS using PHP and MySQL, delivering bespoke workflows and complex data models for global enterprise clients.
- Significantly reduced production regressions by introducing comprehensive test suites to a large legacy codebase.
- Executed incremental refactors to modernize legacy systems while ensuring zero downtime and maintaining strict backwards compatibility.
- Mentored 3 Engineers on authentication patterns and enterprise integration through pair programming.
- Optimized MySQL for CMS platform serving numerous sites; reduced page load time.
Purple Bridge Publishing
January 2015 - September 2016
Senior Full Stack Engineer | Team Lead
Contract
PHP
MySQL
LAMP
PHPUnit
Laravel
Jenkins
Docker
CI/CD
- Led delivery of complex enterprise web applications on LAMP stack; established engineering standards including code style guides and security policies reducing incidents.
- Designed normalized data models and RESTful APIs handling complex educational content management and regulatory compliance for UK schools.
- Established PHPUnit testing and TDD; drove coverage and reduced production bugs.
- Pioneered Docker and Jenkins CI/CD; reduced deployment time from 2 hours to 10 minutes enabling daily releases.
- Mentored engineering team of 6 through code reviews, interviews, and design sessions focused on architectural thinking.
- Optimized MySQL for concurrent users; improved load times through indexing and caching.
MediaCode London
May 2006 - October 2014
Senior Full Stack Engineer
PHP
Laravel
MySQL
jQuery
Architecture
- Built and maintained custom enterprise software and system integrations for financial services, healthcare, and e-commerce clients delivering solutions across diverse domains.
- Owned end-to-end requirements discovery and specification; produced technical architecture diagrams and design documents aligned with business objectives.
- Systematically optimized legacy system performance; implemented database indexing, query optimization, and caching improving response times
- Provided 24/7 production support with critical issue resolution; maintained uptime SLAs and built operational runbooks.
- Mentored multiple generations of Engineers on Laravel, database design, API development, and debugging techniques; conducted numerousinterviews.
- Designed and optimized complex schemas for diverse domains; implemented proper normalization and backup procedures ensuring data integrity.
Orange
March 2001 - February 2006
Business Support Analyst
Reporting
Automation
Data Strategy
Operations
- Engineered technical integrations and automated reporting for telecommunications services serving 10 European countries with an extensive customer base; connected disparate legacy systems enabling real-time data visibility.
- Established development standards and code review practices across operations teams, reducing defects.
- Spearheaded digital transformation from manual processes to automated workflows; built tools and dashboards reducing administrative overhead.
- Designed data warehouses and reporting schemas enabling business intelligence for C-suite strategic decisions.
- Mentored junior developers on troubleshooting and database optimization; conducted technical interviews.
- Maintained 24/7 on-call availability for mission-critical billing systems resolving critical issues within SLAs.
HSBC
1997 - 2001
Software Developer
Online Banking
Web Apps
Security
Compliance
- Developed mission-critical online banking software with stringent security requirements; implemented SSL encryption, input validation, and threat modeling.
- Ensured regulatory compliance with banking standards (BSA, AML, KYC); embedded controls into product design and testing.
- Facilitated cross-functional collaboration across product, systems, QA, operations, and risk teams; shipped features maintaining uptime.
- Supported full lifecycle from requirements through production; maintained 24/7 on-call rotation for critical incident resolution.
- Developed core banking features (transaction processing, account management, reporting) with rigorous QA and security testing.
- Optimized complex database systems storing terabytes of transactional data; ensured data integrity and backup/recovery.
Next Ltd
1994 - 1997
Software Developer
Web Apps
Security
Reliability
SDLC
- Built customer account and transaction web applications for Next's online division; implemented transactional integrity and comprehensive audit logging.
- Contributed across full lifecycle including requirements analysis, design, implementation, testing, and deployment meeting regulatory timelines.
- Implemented security best practices including password hashing, secure session management, and encryption ensuring PCI compliance.
- Supported production systems through rapid incident response; participated in 24/7 on-call rotation for mission-critical banking infrastructure.
- Learned fundamental software engineering principles in disciplined corporate environment; developed expertise in requirements-driven development and compliance-first design.
- Designed database schemas for transaction systems; understood ACID properties and data consistency requirements for critical systems.
Architecture
How I think about systems
Distributed systems fail in predictable ways. I design for failure modes, observability, idempotency and operational simplicity before feature code — and treat cost and developer experience as first-class constraints.
Full stack flow
React
API Gateway
Node.js / TypeScript services
Event / Queue layer
Workers
PostgreSQL / DynamoDB / Redis
AI as a production subsystem
Application
AI Orchestrator
LLM
Tools
APIs
Data
Evaluation / Observability
- Failure modes
- Scalability
- Observability
- Idempotency
- Asynchronous processing
- Event-driven architecture
- Security
- Operational simplicity
- Data access patterns
- Cost
- Developer experience
Applied AI
AI Engineering
I build AI systems as software systems.
AI agents, LLM orchestration and tool calling are production subsystems like any other. I design agent workflows with the same discipline I apply to payment and identity systems — structured outputs, evaluation, observability, security and reliable integration with the systems around them.
My advantage is combining AI with software architecture, distributed systems and production engineering. The model is a component; the system is what I build.
- AI agents & multi-step workflows
- LLM orchestration & tool calling
- Structured outputs & validation
- Evaluation & regression testing
- Observability & cost control
- Security, auth & guardrails
- Production integration & deployment
Opportunities
Currently interested in
I'm drawn to problems where reliability and scale come from decentralised design — peer-to-peer networking and distributed systems that stay resilient without single points of failure.
Senior / Staff Full Stack Engineering
Platform Engineering
Node.js / TypeScript Engineering
Distributed Systems
Peer-to-peer Networking
Applied AI / AI Platform Engineering
Remote / UK / European opportunities