Work
Engineering in production, on three continents.
Each engagement is listed with its context: where the engineering was delivered, when, and with what.
2025–present
Payments
Payment systems for North America
Securing and shipping payment systems for the tipping industry, integrated with card-network processors.
- Context
- Engineering delivered at eTip · San Francisco, USA
- Stack
- Kotlin · Spring Boot · AWS · PostgreSQL · Stripe · TabaPay
2023–2025
Conversational AI
A secure AI assistant, and the platform beneath it
Infrastructure, architecture and core services for a growing company, then a cross-platform AI chat with retrieval-augmented generation on top: a Kotlin Multiplatform customer portal on JVM, web and Android, a WebAssembly chat client, a migration to Azure Container Apps, and a delivery pipeline rebuilt to deploy 20% faster.
- Context
- Engineering delivered at Gensert Technologies · Nauheim, Germany
- Stack
- Kotlin Multiplatform · Compose · Wasm · Spring Boot · Azure · Terraform · MongoDB
2023–20242020–2021
Logistics
Carrier tracking across West Africa
Carrier onboarding, shipment tracking and automatic mission assignment for road freight in Senegal and the region: services in hexagonal architecture, a Kafka bridge from GPS tracking, micro-frontends and a mobile app, with a five-person engineering team under our lead.
- Context
- Engineering led at Gamma Link · Dakar, Senegal
- Stack
- Spring Boot · Kafka · Traccar · Kubernetes · Argo CD · AWS · Next.js · React Native
2023–2024
Legal & translation
Rebuilding a fifteen-year-old translation platform
A broker between clients and automatically selected translators, moved from an undocumented legacy LAMP stack to a modular Spring Boot application, and delivered ahead of the 2024 e-invoicing rules for its clients in Spain.
- Context
- Architecture delivered at Robotistgroup · Geneva, Switzerland
- Stack
- Java · Spring Boot · HTMX · Alpine.js · AWS App Runner · Cognito · RDS · Terraform
2022–2023
Digital identity
Verifiable credentials for Norway and African markets
A self-sovereign identity platform for issuing and verifying credentials, used by companies in Norway, Nigeria, Uganda and Kenya: a legacy monolith rebuilt as services behind a micro-frontend progressive web app, and an interoperable credential issuance API co-developed at JFF PlugFest 2.
- Context
- Engineering delivered at Diwala · Oslo, Norway
- Stack
- SSI · DIDComm · React · Single-SPA · Next.js · GraphQL · GCP · Terraform
2021
Public sector · Finance
Payment tooling for Senegal’s Treasury
Software development kits and applications that route every payment to the agencies entitled to it, whatever the payment method, consolidated into one library; alongside contributions to state interoperability (SUT, NINEA) and the design of a blockchain-secured e-voting platform.
- Context
- Engineering delivered at Modelsis · Dakar, Senegal
- Stack
- Java · JHipster · Angular · Oracle · PostgreSQL · Jenkins
2020
Health
Medical appointments, online and offline
Appointment booking with video and audio consultations in the browser, and a USSD channel for regions without internet or electricity, on a Spring Cloud microservice backend.
- Context
- Engineering delivered at Senvitale · Dakar, Senegal
- Stack
- Spring Boot · Spring Cloud · Twilio · WebRTC · USSD · Angular · AWS
Our products
We build products, and we run them.
Operating our own software in production means we live with the consequences of every architectural decision we recommend.
ęxaucæ product
Lectio
Scripture, lectionary, sermons and hymns for churches, with reading plans and personal notes. One product across the App Store, Google Play and the web.




ęxaucæ product
Sanjola
Choir management for parishes from Dakar to Kinshasa: songs, singers, rehearsals and attendance, on every singer’s phone. In French, English, Wolof and Lingala.




Built for a medical practice
SantéMentaleAfro
A bilingual mental-health platform for a physician’s practice, with online booking, analytics and a design system built to evolve with its owner.




Tell us about the system you need to build.
A short call is usually enough to know whether we are the right firm. If we are not, we will say so, and point you to someone who is.
Excellence is how we thank you for your trust. Care is how we keep it.
Chrys NgomaFounder & principal architect