Senior backend, platform, infrastructure, LLM application, fintech, and data-heavy roles.
7 years in techBackend systemsCloud infrastructureLLM application engineering
Senior backend engineer for products that need scale, speed, and trust.
I am Ayomiku John. I build TypeScript, Node.js, Python, FastAPI, PostgreSQL, Redis, Socket.IO, AWS, GCP, fintech, edtech, AI, crypto, social, and mobile-backed systems where reliability is part of the product.
Resume stack
Production stack across backend, AI, cloud, fintech, and mobile-backed systems.
Grouped by the systems I have shipped, operated, and improved under real product constraints.
01
Languages and frameworks
Used across backend services, admin dashboards, mobile-facing APIs, and modernization work.
TypeScriptJavaScriptPythonFastAPINode.jsExpressNestJSReactNext.jsGraphQLPrisma
02
Data and realtime systems
Operated PostgreSQL at billion-record scale and built realtime experiences for chat, feeds, and notifications.
PostgreSQLMySQLMongoDBRedisPgBouncerSocket.IOWebSocketsBullRabbitMQ
03
Cloud and DevOps
Hands-on infrastructure ownership across AWS, Google Cloud, Azure, CI/CD, monitoring, and cost control.
AWS EC2RDSS3LambdaCloudWatchCloudFrontGCP Cloud RunCloud SQLAzureDockerKubernetesTerraformNginx
04
Fintech and product integrations
Provider-heavy backend work where transaction state, recovery, and auditability matter.
PaystackQuidaxDojahKYCWallet ledgerP2P adminBlockchain RPCTrading bot flows
05
Quality, security, and delivery
Built delivery systems around testing, rollback, observability, permissions, and production response.
GitHub ActionsGitLab CIPlaywrightCloud ArmorIAMRate limitingBackupsRollback plansMonitoring
06
LLM application engineering
Built LLM-backed features with tool access, retrieval context, structured model output, streaming UX, and background execution.
DeepSeekOpenAI APIsMCP serverLLM tool callingFunction callingStructured outputsJSON schemaRAGContext engineeringStreaming responsesModel evalsAsync model jobs
Hiring signal
Production constraints I have worked through.
Large data, async AI work, wallet risk, realtime chat, provider failure, admin control, and cloud cost are part of the work.
Backend systems
API, auth, permissions, data modeling, queues, cache layers, realtime messaging, and worker pipelines for live product traffic.
Data scale
PostgreSQL pressure solved with indexes, partitioning, materialized views, query rewrites, read replicas, and Redis read paths.
Production ownership
Monitoring, deployments, automated backups, rollback paths, Nginx, rate limits, load balancers, cloud cost, and incidents.
Product risk handling
Built around risk: wallet transaction state, document quality gates, student learning flows, admin tooling, identity checks, and safety-sensitive media.
Cross-domain product systems
Delivered product areas across edtech, social, crypto, ads, LLM tooling, admin operations, and mobile-backed platforms.
Can walk through read-heavy PostgreSQL design, queue boundaries, cache invalidation, realtime messaging, and failure recovery.
Can explain monitoring, alerting, rollback paths, automated backups, deployment pipelines, and why expensive work should leave request paths.
Can defend indexes, materialized views, read replicas, Redis strategy, CDN placement, autoscaling, and cost decisions.
Can translate messy business pressure into safer flows for wallets, LLM tools, retrieval context, admin actions, and student UX.
Engineering scope
Product surfaces across backend, mobile, admin, ads, AI, and operations.
These are the production areas behind the public products: user flows, internal controls, background workers, billing paths, LLM systems, and operational tooling.
AI, learning, wallet, ads, and operations backend
Routes and workers cover LLM learning APIs, practice generation, material chat, academic extraction, ChatGPT/MCP access, token usage, student wallets, Paystack webhooks, ads billing, and admin health.
Student-facing app experience
Mobile surfaces include practice studios, learning chat, notifications, upload queue management, deep links, ads, Crashlytics, and API clients for the learning platform.
Internal operations and product control
Admin surfaces include aspirant generation readiness, subscription limits, AI token usage, school access, self-serve ads review, student wallets, and health monitoring.
Self-serve campaigns and monetization
Campaign tooling covers FCM/email campaign creation, scheduled campaigns, billing wallet, subscriptions, pending reviews, in-app ads, blog ads, campaign stats, and delivery failure states.
MCP, retrieval, tools, and structured model output
The surrounding workspace includes an MCP server, OAuth/PKCE connection flow, read-only tool schemas, material extraction workers, retrieval context, class-note enhancement, and LLM web-search source handling.
Engagement model
Contract roles and startup product roles are separate paths.
A contract role needs a defined technical outcome. A startup product role needs longer-term ownership across architecture, roadmap pressure, and production operations.
Startup product role
For teams that need long-running product ownership.
Edtech and LLM learning
I can build learning assistants, practice generators, content ingestion, retrieval pipelines, learning progress, subscriptions, and admin review systems.
Social and media products
I can build feeds, follows, comments, messaging, notifications, moderation hooks, upload queues, recommendations, and media delivery paths.
Crypto and fintech
I can build wallet backends, provider integrations, KYC, payment rails, transaction state machines, settlement flows, and admin recovery tools.
Contract role
For teams that need a defined senior engineering outcome.
Senior backend contract
Short or medium-term backend ownership for APIs, database work, queues, integrations, production fixes, and platform rebuilds.
AI engineering contract
LLM feature delivery for MCP servers, tool-calling APIs, retrieval pipelines, structured outputs, streaming chat, evals, and quality controls.
Infrastructure contract
Cloud, monitoring, deployment, cost control, backup, Nginx, Redis, worker, and reliability work for live products.
Selected systems
Products I have helped build, scale, and operate.
Each case study is framed around the problem, the architecture, and the result.
Edtech, AI, mobile, admin, ads
AbS
A learning ecosystem across Flutter mobile, backend, web admin, ads, wallets, LLM learning tools, practice generation, academic-library ingestion, and student collaboration.
Problem
Students needed fast access to past questions, materials, LLM-powered study help, chat, and campus-specific learning while the data layer grew into billions of records.
Architecture
Split user APIs, admin flows, LLM workflows, background extraction, Redis caching, Socket.IO realtime features, object storage, and PostgreSQL read paths around the heaviest access patterns.
Result
Reduced API latency by 45%, kept the system usable through 4B+ records, and supported thousands of student users through mobile and admin surfaces.
Stack
Node.js, TypeScript, Express, Prisma, PostgreSQL, Redis, Socket.IO, AWS, Flutter, Next.js
Crypto wallet, AI-heavy trading, Naira payout, payment rails
HelloBob
Backend systems for a mobile crypto wallet where users deposit, withdraw, swap, sell, transfer, use AI-heavy trading flows, and settle into Nigerian bank accounts.
Problem
Wallet products fail when transaction states, third-party providers, blockchain RPC calls, identity checks, and payout flows are not modeled carefully.
Architecture
Integrated Quidax, Dojah, Paystack, P2P admin operations, AI-heavy trading-bot workflows, Socket.IO messaging, secure wallet flows, AWS infrastructure, backups, monitoring, and rollback-ready CI/CD.
Result
Supported daily feature delivery, high-concurrency mobile usage, safer transaction handling, monitored infrastructure, AI-backed trading execution, and a 99.8% uptime operating target.
Stack
Node.js, TypeScript, PostgreSQL, Socket.IO, AWS, Docker, Paystack, Quidax, Dojah, trading bot workflows
Sports social network and media platform
DigiYo
Backend and infrastructure for a sports social product with video challenges, feeds, messaging, recommendations, moderation needs, and AI media generation.
Problem
The product needed social graph behavior, fast media delivery, realtime engagement, async AI generation, and safety-sensitive content flows without blocking the app.
Architecture
Modeled posts, follows, likes, comments, feeds, notifications, recommendations, Bull/Redis jobs, S3 media storage, CloudFront delivery, Nginx caching, and rate limiting.
Result
Kept API responses under a second during peak periods and moved heavy AI/media work out of request paths through queues and workers.
Stack
NestJS, PostgreSQL, Redis, Bull, Socket.IO, AWS, S3, CloudFront, Nginx
Full-stack modernization and cloud cost control
Bonsaiilabs and BetterMenu
Modernized application delivery, data access, mobile architecture, cloud operations, testing, and performance for customer-facing products.
Problem
The team needed lower delivery cost, simpler maintenance, better data retrieval speed, and infrastructure that could scale without constant manual operations.
Architecture
Migrated mobile delivery from Flutter to React/CapacitorJS, built Google Cloud serverless flows, tuned Cloud SQL, added CDN/load balancing, and hardened security with Cloud Armor and IAM.
Result
Removed $30K in annual development cost and improved data retrieval speed by 80% through targeted architecture and data-flow work.
Stack
React, CapacitorJS, Node.js, PostgreSQL, Google Cloud, Playwright, Cloud Armor
Architecture
Simple diagrams for the systems behind the claims.
Simplified views of major flows I worked on: request boundaries, async jobs, data stores, providers, and recovery paths.
AbS learning platform
High-volume learning data, LLM workflows, realtime chat, and admin operations.
01
Flutter, web admin, ads
02
API, auth, permissions
03
Library, chat, AI, wallets
04
Redis, queues, workers
05
PostgreSQL 4B+, object storage
Optimized slow reads with indexes, materialized views, and cache-first paths.
Moved document extraction, model generation, and repeated work away from request paths.
Kept student UX, admin control, and background processing connected to the same source of truth.
HelloBob wallet backend
Transaction-safe backend for wallet, payment, crypto, identity, and settlement workflows.
01
Mobile wallet
02
API, auth, KYC
03
Wallet ledger, P2P admin
04
Quidax, Dojah, Paystack
05
Monitoring, backups, rollback
Treat third-party providers as unreliable boundaries with explicit transaction state.
Design backend flows around idempotency, observability, and operational recovery.
Connect wallet actions, messaging, settlement, and admin visibility without exposing internal complexity.
Technical depth
Technical areas I can defend under interview pressure.
Data systems
PostgreSQL at billion-record scale, query plans, indexes, partitioning, read replicas, materialized views, Redis cache strategy, and operational data cleanup.
Reliability
Health checks, CloudWatch dashboards, rollback-ready deployments, automated backups, rate limiting, Nginx, load balancers, and production incident debugging.
Fintech backend
Wallet flows, identity/KYC providers, Paystack payout/payment work, Quidax crypto rails, P2P admin operations, transaction safety, and provider failure handling.
LLM application engineering
MCP server, OAuth-protected tool access, structured outputs, retrieval context, async workers, model evaluation paths, queue-based media jobs, and validation gates around noisy inputs.
Realtime systems
Socket.IO chat, notifications, live social interactions, Redis-backed async jobs, messaging history optimization, and mobile-first concurrency concerns.
Delivery leadership
Scoped ambiguous product requirements, mentored developers, managed CI/CD, shipped mobile/backend/admin features, and translated business pressure into technical execution.
Experience
Seven years in tech, focused on systems that have to work in production.
2025
Senior Backend Engineer
DigiYo
Built backend infrastructure for a sports social platform with AI media jobs, realtime messaging, recommendations, social graph features, and scalable AWS delivery.
2023 - 2025
Senior Project Manager and Infrastructure Lead
AbS
Led product, backend, infrastructure, AI, mobile, and admin delivery for a Nigerian education platform used by thousands of students.
2024 - 2025
Backend Engineer
HelloBob
Built wallet, messaging, payment, crypto, trading, and infrastructure systems for a mobile crypto product with Naira settlement.
2022 - 2024
Senior Full-stack Developer
Bonsaiilabs
Delivered app modernization, cloud infrastructure, serverless systems, testing, cost reduction, and performance improvements.
Next role
Bring me into backend, AI, fintech, edtech, social, or infrastructure problems with real production constraints.
Contact
Let's talk if the work needs senior backend ownership.
Strongest areas: backend platforms, LLM application systems, fintech rails, edtech workflows, realtime systems, infrastructure repair, and contract delivery with clear scope.
EmailAyomikuolatunji@gmail.com
Download CVayomiku_feb_resume.pdf
AvailabilityRemote contract or senior product roleLagos, Nigeria