David Tandoh in a grey checked blazer and round glasses, looking straight at the camera.
David laughing with his arms crossed, in a white T-shirt.
David leaning on a stone bridge in a Cotswolds village, a river and stone cottages behind him.
David on a woodland trail in a long coat and boots, camera in hand, looking back down the path.
David wearing a riding helmet and sitting on a chestnut horse.
David in a wool beanie and dark coat, looking down into the camera under a clear sky.

PDavid Tandoh, Senior Software Engineer

I build AI platforms and agentic systems that are safe to run in production.

AI Platform Engineering

Senior software engineer with eight years in financial services. I design AI platforms, agentic systems and fraud analytics that hold up under real traffic and regulation. Founder of GuideX, a travel marketplace for Africa. Working remotely across the UK and Africa.

01The human

Eight years where mistakes cost money.

I’m David, a senior software engineer who has spent eight years building systems where mistakes cost money: payment switches in Ghana, fraud platforms for a UK bank, and now enterprise AI.

Recently I architected an internal AI platform that gives 50+ engineers secure access to 22 models through one gateway, with cost controls, guardrails and full tracing. I built the developer tooling that standardises how teams code with AI agents, and delivered fraud analytics that cut false positives by 35%.

Outside work I founded GuideX, an AI-enabled travel marketplace for African tourism, live on iOS and Android. I also run my own fleet of coding agents across two machines, and I write about how it works.

02Principles

Three rules I build by.

On the desk right now

  1. 01Running an enterprise AI platform that gives 50+ engineers one secure gateway to 22 LLMs.
  2. 02Scaling GuideX, a travel marketplace for African tourism, live on iOS and Android.
  3. 03Running Firstmate as the chief-of-staff layer for a crew of coding agents after retiring Bosun.
  4. 04Shipping LLM-assisted fraud analytics for a UK bank.
  5. 05Mentoring underrepresented young people in tech with Kocha Mentors CIC.

03Work with me

Bring me the system that has to hold.

I take on work designing and building AI platforms, agentic systems and risk analytics, especially where reliability, observability and governance matter. Remote, across the UK and Africa.

Remote · UK & Africa

Three ways to start

Intro call
You have a problem and want a straight read on it.
A short conversation about the system, the constraint and whether I am the right person.
Scoped build
You know the outcome and need it designed and shipped.
A fixed scope with a written plan, working software at each milestone and a documented handover.
Embedded lead
Your team needs senior hands on a platform or agentic programme.
I join the team part time, set the architecture and standards, and build alongside your engineers.

Book a call

Choose a call, then a time that suits you. Tell me about the system, the constraint and what good looks like.

Loading the calendar

Open my booking page on Cal.com or email [email protected].

04.1Case study

Enterprise AI platform

In productionbigspark · internal platformArchitect and lead engineerCurrent role

LLMs behind one API
22
Engineers served
50+

Problem

Every team that wanted to build with LLMs had to integrate providers, manage credentials and watch its own spend. That slowed delivery and left governance to chance.

Approach

  • Architected a secure gateway that serves 22 enterprise LLMs, including Claude, GPT, Llama and Qwen, through one unified API.
  • Deployed on AWS with LiteLLM, ECS Fargate, Bedrock, Terraform, ALB and WAF, with multi-tenant governance, self-service provisioning and enterprise guardrails.
  • Built a developer portal in React, TypeScript, FastAPI and Cognito for self-service access, model discovery and credential management.
  • Added MLflow tracing for end-to-end visibility into prompts, latency, cost and model behaviour.

Outcome

  • 50+ engineers build AI-powered products without managing provider integrations.
  • Organisation-wide budgets are enforced and spend is visible.

AWSLiteLLMECS FargateBedrockTerraformWAFMLflowReactFastAPICognito

04.2Case study

AI developer experience

In productionbigspark · agentic engineeringDesigner and engineerCurrent role

Repositories standardised
15+
Authenticated agent access
MCP

Problem

AI coding assistants arrived team by team, each with its own prompts, habits and risks. Output quality depended on who was driving.

Approach

  • Designed an internal AI developer platform that standardises AI-assisted development for Claude Code, Cursor, Kiro and GitHub Copilot.
  • Built a reusable ecosystem of agentic workflows, context engineering, versioned AI assets and guardrails.
  • Deployed secure Model Context Protocol (MCP) infrastructure on AWS ECS, exposing enterprise services and knowledge bases to agents through authenticated interfaces.

Outcome

  • One standard for AI-assisted development across 15+ repositories.
  • Consistent code generation and less onboarding effort for new engineers.

Claude CodeCursorKiroGitHub CopilotMCPAWS ECS

04.3Case study

Fraud analytics

In productionA UK bank · via bigsparkSenior engineerCurrent role

Fewer false positives
35%
Projected annual saving
£5m
Less call-handling time, up to
50%

Problem

Fraud teams were working through too many false alarms, and new scam types such as invoice redirection needed detection that fits strict UK banking regulation.

Approach

  • Built and automated the core infrastructure for an ML-driven fraud detection system with the data science team.
  • Led the architecture and implementation of an invoice redirection scam detection application.
  • Designed a signal-driven risk pipeline that aggregates indicators and applies LLM-assisted classification for investigation workflows.
  • Contributed to an internal fraud agent tooling platform that joins data from multiple systems for case investigation.

Outcome

  • False positives fell by 35%, with a forecast business impact of £2.5m a year.
  • Invoice redirection detection carries a projected saving of £5m a year.
  • Investigator call-handling time fell by up to 50%.
  • Production data pipeline failures fell by 35% through proactive monitoring and self-healing.

ScalaSparkKafkaSnowflakeAWSTerraformGitLab CI/CD

04.4Case study

GuideX

LiveTravel marketplace · FounderFounder and technical lead2024 to present

iOS, Android and web
Live
First market
Ghana

Open the live siteGet it on the App StoreGet it on Google Play

GuideX home screen: Discover your next memory, with a Start exploring button and hosted experiences in Ghana.

Problem

Travellers who want to experience Africa struggle to find and trust local hosts, and hosts have no simple way to take bookings and get paid.

Approach

  • Designed and built the mobile app, backend platform, booking infrastructure and cloud architecture, leading product strategy from concept to production.
  • Shipped native iOS and Android apps for discovery, booking, in-app chat, QR-code tickets and payments.
  • Built a two-sided marketplace with host identity checks through SmileID and payments in Ghanaian cedis through Paystack.
  • Built an AI site-reliability agent that investigates log errors from the app and cloud infrastructure, with a human approving each case before a coding agent picks it up.

Outcome

  • Live on the App Store, Google Play and the web, starting with hosts in Ghana.
  • Discovery, booking, payment and host verification run on one platform.

FlutterNext.jsTypeScriptKotlinSpring BootFirebaseGoogle CloudPaystackSmileIDLangGraph

04.5Case study

Bosun

SupersededAgentic orchestration · PersonalCreator and engineer2026

Orchestrator loop
24/7
Approval gate
Fail-closed

Read the Firstmate transitionRead the historical Bosun write-up

Problem

Running a dozen coding agents means a dozen terminals to watch, and one careless command can force-push, deploy or delete.

Approach

  • A deterministic 24/7 outer loop watches agents and dispatches ready work in plain code, so autonomy stays in the inner loops.
  • A tiered, fail-closed approval gate: routine work runs free, while force-push, deploy, rm -r and secrets pause for a tap on the phone.
  • Per-project Kanban boards hold durable state, so a crashed orchestrator rebuilds from card status.
  • Live spend telemetry, a cheaper default model and a hard daily cap keep cost bounded.

Outcome

  • One conversation replaces a wall of agent terminals.
  • Risky commands cannot run without a human decision.
  • Firstmate superseded Bosun as the chief-of-staff layer.

PythonOmnigentHermesLLM agentslaunchdKanbanCEL

04.6On the bench

Also in the workshop.

05The journey

From card switches in Accra to AI platforms in the UK.

Each role added a layer: payment rails, then regulated data platforms, then the AI systems that run on both.

  1. Jun 2021 to present

    Senior Engineer

    bigspark, for a UK bank, Nottingham, UK

    Enterprise AI platform, AI developer experience, fraud analytics and platform leadership for a UK bank.

    • Architected a secure gateway to 22 enterprise LLMs, used by 50+ engineers.
    • Standardised AI-assisted development across 15+ repositories and deployed MCP infrastructure on AWS ECS.
    • Built ML-driven fraud detection infrastructure that cut false positives by 35%, with a forecast impact of £2.5m a year.
    • Led an invoice redirection scam detection application with a projected saving of £5m a year.
    • Established and mentored an offshore engineering team in Ghana.

    Why it matters. Regulated finance, cloud platforms and applied AI in one role: the blend behind banking’s move to intelligent, automated risk.

  2. Jan 2021

    MSc, Software Engineering for Financial Services

    University of Leicester, Leicester, UK

    Master’s degree focused on engineering for financial systems.

    • Awarded Best MSc Student in Software Engineering for Financial Services, 2020.

    Why it matters. Formal grounding in financial systems, the foundation under the DXJ Signal Engine.

  3. Jul 2018 to Sep 2019

    Card Systems Engineer

    EProcess International (Ecobank), Ridge, Accra, Ghana

    Owned critical card-payment systems and scheme integrations for a pan-African bank.

    • Managed and supported Postilion Realtime and Postilion Office card systems.
    • Led projects integrating National Payment Switches with the bank’s core payment switch.
    • Technical liaison for international card schemes, including VISA and Mastercard.
    • Redesigned incident management and escalation, cutting incident response time by 50%.

    Why it matters. Deep payments-rails experience with ISO 8583, switching and card schemes: the operational reality behind modern fintech.

  4. Aug 2016 to Jul 2018

    EFT Software Engineer

    Electronic Funds Technology Corporation, Labone, Accra, Ghana

    Payment integrations for card processing across multiple African markets.

    • Developed Java-based payment integrations and reconciliation tooling on the Postilion Framework.

    Why it matters. Where it started: the discipline of money-moving systems that cannot fail.

  5. Jun 2016

    BSc, Computer Science

    Ashesi University, Berekuso, Ghana

    Computer Science degree from one of Africa’s leading universities.

    • Foundations in software engineering, algorithms and systems.

    Why it matters. Rigorous fundamentals that scale from card switches to AI agents.

06Capabilities

The toolkit, by layer.

AI platforms and LLM engineeringDatabricks Certified Generative AI Engineer Associate
LiteLLM gatewaysBedrockOpenAIAnthropicMCPRAGVector databasesEmbeddingsTool callingMLflowEvalsContext engineeringHarness engineering
Agentic engineering
CrewAILangChainLangGraphClaude CodeCursorCodexKiro
Cloud and DevOps
AWSAzureGCPDockerKubernetesTerraformGitHub ActionsGitLab CI/CD
Data engineeringDatabricks Certified Data Engineer Associate
DatabricksSparkSnowflakeKafkaAirflowPostgreSQLMongoDB
Languages and frameworks
JavaKotlinSpring BootPythonFlaskScalaGoC#ReactRESTGraphQL
Fintech and payments
ISO 8583ISO 20022Payment switchesFraud detectionPCI DSSPostilion
Quality and practice
TDD and BDDJUnitMockitoJestKotestTestcontainersAgile

07Credentials

Certified, and checkable.

Certified by Databricks in data engineering and generative AI engineering, and by Anthropic and Microsoft. Every card opens the issuer’s public record.

Cloud platforms

Awards

Verified credentials. Each issuer confirms its own record through the links above. The full list is also on my LinkedIn profile and my Credly profile.

08Let’s build

Have a system that has to hold? Let’s talk.

I take on contracts in AI platforms, agentic systems and risk analytics. The quickest route is a short call.