Case Study
Fitness Class Scheduler
A modern Angular SSR application for planning weekly fitness classes
A modern Angular SSR application for planning weekly fitness classes
Role: Frontend Developer
View Case StudyHi, I'm Ancel Ajanga
Systems Engineer & Fullstack Developer building fault-tolerant, scalable, and real-time applications.
Systems Engineer focused on scalable, reliable software systems and modern web applications.
Independent systems engineer focused on scalable, reliable software architecture.
Also contributing part-time as an AfterQuery Expert Software Engineer.
Open to collaborations and engineering opportunitiesFrom executing zero-knowledge frontends to orchestrating asynchronous Kafka microservices, I design and ship production systems built to handle millions of requests natively. I don't just write features—I build the bedrock that allows companies to scale safely.
Fullstack Developer — Resilience & Scale at Every Layer
Hardened Backends
NestJS, PostgreSQL, fail-safe logic. Transactional correctness and auditability by default.
Fluid Frontends
Flutter, React, UX and performance. Responsive, accessible, built for real users.
Self-Healing Infra
Redis, BullMQ, automated recovery. Graceful degradation and observability when things fail.
10K+
Users Supported
50+
API Endpoints
Multi-Tenant
Architectures
~97%
Uptime Maintained
100–200ms
P95 Latency
200–1000
Concurrent Users
About Me
Ancel Ajanga
Fullstack Software Engineer & Systems Architect
Nairobi, Kenya (from Narok)
Started coding in 2021
Systems Engineer & Fullstack Developer
Professional Focus
Focused on systems engineering, architecture, and modern web applications across web, backend, and distributed systems.
Alongside independent engineering work and personal systems projects, I also contribute part-time as an AfterQuery Expert Software Engineer.
About Me
Hi, I'm Ancel Ajanga (also known as Duke), a Staff Software Engineer & Lead Systems Architect specializing in distributed systems and high-performance engineering. I build production-grade backbones — from meticulously crafted UIs to resilient distributed backends — with a relentless focus on performance, reliability, and transactional integrity.
Based in Nairobi, Kenya, I specialize in architecting systems that bridge the gap between AI-driven automation and production safety. My expertise spans four key domains:
Resilient Fullstack Systems: I build end-to-end platforms like NestFi, combining hybrid storage with strict ledger integrity to solve the 'Blind Trust' problem in financial engineering.
Infrastructure & Intelligent Operations: I design self-healing systems such as Aegis, where machine learning is gated by OPA policies and cryptographically signed intents.
Data & Privacy Architecture: In projects like Inkly, I implement Zero-Knowledge cryptographic lifecycles to ensure data sovereignty in collaborative environments.
Frontend Engineering & UI Systems: I engineer robust interactive architectures and fluid interfaces. Discover my UI Experiments & Frontend Labs to see how I balance rigorous performance metrics with highly creative interaction design.
From real-time WebSocket-driven platforms (SignFlow) to multi-tenant SaaS architectures (EduManage), I focus on service isolation, containerization, and fault-tolerant design patterns. I don't just build features—I design the systems that keep products stable, secure, and scalable as they grow.
Technical Skills
React95%
TypeScript90%
JavaScript95%
Node.js85%
Python80%
Django85%
Flutter75%
Dart75%
Vue.js80%
Angular75%
MongoDB75%
PostgreSQL80%
MySQL70%
Solidity70%
AWS70%
Git85%
Docker65%
Tailwind CSS90%
CSS390%
HTML595%
Key Achievements
10K+ Users Supported
Scalable systems handling thousands of concurrent users
50+ API Endpoints
Enterprise-grade RESTful APIs with comprehensive features
Multi-Tenant Architectures
Secure, isolated systems supporting multiple organizations
Technical Arsenal
Frontend & Mobile
Flutter 3.x (Dart) · Next.js 14 · React 18 · TypeScript · TanStack Query · Material 3 · Tailwind CSS
Backend & APIs
NestJS 10 · Node.js · Prisma ORM · RESTful APIs · WebSockets (Socket.io) · Firebase Admin SDK
Architecture & Reliability
Microservices · Multi-tenant SaaS · Circuit Breakers · Event-Driven Design · Distributed Systems
Infrastructure & Cloud
Kubernetes (K8s) · Docker · Terraform · Prometheus & Grafana · Cloudflare · Render · Netlify
Data & Security
PostgreSQL (Transactional) · MongoDB (Logs) · Redis (Caching) · HMAC Signature Verification · JWT/RBAC
Specialized Tech
AIOps (Anomaly Detection) · Double-entry Ledgers · Cryptographic Hash Chains · Twilio OTP
Technologies & Tools
Frontend
ReactVue.jsAngularTypeScriptJavaScriptHTML5CSS3Tailwind CSSNext.js
Backend
Node.jsPythonDjangoExpress.jsNestJS
Mobile
FlutterDartReact Native
Database
MongoDBPostgreSQLMySQLRedisPrisma
Blockchain & Web3
SolidityHardhatOpenZeppelinRainbowKitWagmiethers.jsIPFS
Cloud & DevOps
AWSDockerGitCI/CD
Tools
VS CodeFigmaPostmanGitHub
Career Goals
Lead Technical Teams
Aspire to lead development teams and mentor junior developers in creating innovative solutions.
Build Scalable Products
Create applications that can handle millions of users and make a significant impact in the tech industry.
Contribute to Open Source
Give back to the developer community by contributing to meaningful open-source projects.
Start a Tech Company
Eventually launch my own technology company focused on solving real-world problems in Africa.
Professional Experience & Education
Lead Systems Engineer (Independent Consultant)
March 2024 – Present
Architecting resilient, production-grade infrastructure and financial systems for private clients and enterprise-level scale.
- NestFi (Fintech): Engineered a resilient financial coordination platform using a PostgreSQL/MongoDB hybrid architecture to ensure ACID compliance for transactions while maintaining high-throughput event logging for asynchronous mobile money payments.
- Aegis (AI-Driven Security): Developed an autonomous infrastructure monitoring system that uses AI to detect behavioral anomalies and execute controlled remediation actions within strict isolation boundaries.
- LedgerX (Enterprise Finance): Built a multi-tenant finance engine featuring a SHA-256 Cryptographic Hash Layer, creating an immutable, tamper-evident audit trail for every financial record.
Software Engineer (Contract & Project Lead)
Focused on scaling operational platforms and complex multi-tenant SaaS architectures.
- OpsFlow (Operations Management): Designed a real-time incident response platform using WebSockets for sub-second synchronization and a dual-database strategy to separate transactional workflows from analytical reporting.
- EduManage (Multi-tenant SaaS): Architected a school management system with Hierarchical RBAC and strict tenant isolation, ensuring secure data boundaries for multiple institutions on a single shared infrastructure.
- Full-Stack Development: Delivered various production-ready solutions (RoadRescue, HeartSync) focusing on React performance and clean code standards.
Education
- B.S. in Computer Science — Currently Enrolled (Part-time)
- Diploma in Software Engineering — Completed
- Full Stack Development Certificate — Moringa School (2022)
Why Work With Ancel Ajanga?
Stop worrying about system architecture and scalability. I build solutions that just work—and keep working under load.
Production-Readiness
My code isn't just a prototype. It's built with fallback modes, circuit breakers, and comprehensive error handling ready for thousands of concurrent users.
Fullstack Architecture
From defining a robust GraphQL schema to executing pixel-perfect React integrations, I own the entire technology stack end-to-end.
High Performance
Fast applications retain users. I specialize in driving P95 latencies below 200ms using caching and query optimization.
Open to collaborations, engineering opportunities, and ambitious software projects.
Insights from LinkedIn
Long-form engineering breakdowns live here on the site. Connect on LinkedIn for professional updates; use the Developer Journal and guides for architecture narratives you can cite and share.
Ancel Ajanga
Systems Engineer & Fullstack Developer
Same person entity as this portfolio — LinkedIn is listed in Person JSON-LD sameAs for crawlers and answer engines.
Today's Highlights
Curated selection of case studies and insights.
Case Study
NestFi — Resilient Financial Coordination Platform
Correctness-first finance with hybrid storage, M-Pesa B2C, and failure-aware design. Developed by Ancel Ajanga.
Correctness-first finance with hybrid storage, M-Pesa B2C, and failure-aware design. Developed by Ancel Ajanga.
Role: Full-Stack Software Engineer
View Case Study
Case Study
EduChain - Blockchain Certificate Management
Full-stack Web3 application for issuing verifiable academic certificates as NFTs
Full-stack Web3 application for issuing verifiable academic certificates as NFTs
Role: Full-Stack Software Engineer
View Case Study
Case Study
SignFlow - Real-Time Assistive Tech Simulation for Sign Language
Building a high-fidelity assistive technology simulation for real-time sign language translation
Building a high-fidelity assistive technology simulation for real-time sign language translation
Role: Full-Stack Software Engineer
View Case StudyLooking to scale your distributed platforms?
Open to collaborations, engineering opportunities, and ambitious software projects.
Flagship Systems
Enterprise-grade systems showcasing resilient architecture, hybrid databases, and scalable solutions.
Looking to hire a Next.js developer in Kenya or full-stack developer in Nairobi? See my dedicated service page with outcomes and contact details.
Inkly — Secure, High-Availability Messaging Architecture
Inkly is a production-grade, high-availability secure messaging architecture engineered to solve the fundamental conflict between Zero-Knowledge privacy and massive horizontal scalability. Developed by Ancel Ajanga, the system replaces centralized trust models with a decentralized 'Sacred Bond' cryptographic lifecycle while maintaining sub-100ms real-time delivery across distributed WebSocket clusters. The architecture is built on a resilient three-tier storage strategy (PostgreSQL, MongoDB, and Redis) designed to handle thousands of concurrent connections with fault-tolerant delivery guarantees and effortless recovery from high-latency network partitions.
Read Case Study
Aegis — Autonomous Infrastructure Guardrail System
Aegis is a production-hardened Autonomous Infrastructure Guardrail System engineered to bridge the gap between AI-driven remediation and system safety. Developed by Ancel Ajanga, the platform provides a Zero-Trust orchestration layer where AI suggests remediations but execution is strictly gated by human-defined Open Policy Agent (OPA) rules and cryptographic 'Signed Intent' validation. By utilizing a pull-based agent architecture, Aegis scales securely across heterogeneous cloud environments, providing high-availability infrastructure self-healing without compromising the security perimeter.
Read Case Study
NestFi — Resilient Financial Coordination Platform
NestFi is a production-grade financial coordination platform engineered for absolute correctness under the volatility of distributed systems. Developed by Ancel Ajanga, the system addresses the critical failures inherent in mobile money integrations and asynchronous payment processing. By leveraging a hybrid storage strategy and a ledger-first philosophy, NestFi ensures that financial truth is mathematically verified, auditable, and resilient to external provider outages, delayed callbacks, and race conditions. It is a capstone in safe financial engineering for high-risk, low-trust environments.
Read Case Study
Frontend Engineering & Experiments
This section demonstrates advanced frontend engineering, UI systems, and interaction design. These applications showcase my ability to execute demanding layouts, achieve high frame rates, and engineer robust interactive architectures.
Experiment
Personal Finance Tracker
A modern web application for tracking personal income and expenses with visual analytics
2023
2 months
A creative frontend experiment exploring modern UI patterns and data visualization techniques. This project demonstrates Vue 3's Composition API, reactive state management, and interactive charting capabilities for personal finance tracking.
UI Architecture
State management avoids prop-drilling. SVG charts.
Performance
60fps chart rendering via memoization.
Responsive Grid
CSS Grid for dense tabular data on mobile.
Technologies Used
Vue.js 3
TypeScript
Chart.js
Tailwind CSS
Experiment
Fitness Class Scheduler
A modern Angular SSR application for planning weekly fitness classes
2023
1.5 months
A modern Angular SSR application for planning weekly fitness classes with dark mode, responsive design, and client-side persistence.
UI Architecture
Interactive calendar with drag-drop and optimistic UI updates.
Performance
Minimized re-renders, pre-fetched months.
Responsive Grid
Touch-friendly day-view carousel for mobile.
Technologies Used
Angular 20
TypeScript
Angular SSR
Tailwind CSS
Experiment
Habit Tracker & Streak Counter
A Progressive Web App for tracking daily habits and building momentum
2023
2 months
A creative Progressive Web App experiment exploring offline-first design patterns and modern UI interactions. This project demonstrates PWA capabilities, service workers, and engaging visual feedback for habit tracking.
UI Architecture
Accessible Gamification with Framer Motion.
Performance
IndexedDB for local state, offline-first.
Responsive Grid
Fluid SVG streaks from 320px to 4K.
Technologies Used
React 19
PWA
Chart.js
Tailwind CSS
Looking to stabilize a monolithic backend?
Open to collaborations, engineering opportunities, and ambitious software projects.
Tech Stack
Enterprise-grade technologies for building resilient, scalable systems. From hybrid database architectures to microservices, containerization, and real-time communication.
Technology Usage Frequency
How many of my enterprise projects use each technology
Git
12 projects
9/10
Netlify
6 projects
9/10
HTML5
1 projects
9/10
CSS3
1 projects
9/10
JWT
7 projects
8/10
React Router DOM 6
6 projects
8/10
Axios
4 projects
8/10
Mongoose
4 projects
8/10
RBAC
4 projects
8/10
Render
4 projects
8/10
WebSockets
3 projects
8/10
PostCSS
3 projects
8/10
Chart.js
2 projects
8/10
bcryptjs
2 projects
8/10
CORS
2 projects
8/10
Helmet
2 projects
8/10
ESLint
2 projects
8/10
TanStack Query
1 projects
8/10
HMAC
1 projects
8/10
M-Pesa Daraja
3 projects
7/10
Framer Motion 10
2 projects
7/10
Jest
2 projects
7/10
PWA
2 projects
7/10
Django REST Framework
1 projects
7/10
Leaflet.js
1 projects
7/10
Zustand
1 projects
7/10
Hardhat
1 projects
7/10
OpenZeppelin
1 projects
7/10
RainbowKit
1 projects
7/10
Wagmi
1 projects
7/10
ethers.js
1 projects
7/10
IPFS
1 projects
7/10
Pinata
1 projects
7/10
Prometheus
1 projects
7/10
Grafana
1 projects
7/10
Open Policy Agent (OPA)
1 projects
7/10
OIDC
1 projects
7/10
Stripe
1 projects
7/10
BullMQ
1 projects
7/10
Firebase Auth
1 projects
7/10
Recharts
2 projects
6/10
SQLite
1 projects
6/10
Vitest
1 projects
6/10
Playwright
1 projects
6/10
Loki
1 projects
6/10
Tempo
1 projects
6/10
Cloudflare Workers
1 projects
6/10
Turborepo
1 projects
6/10
Technology Categories
Breakdown of technologies by category