Backend engineering
Backend correctness matters when software manages invoices, patients, inventory or transactions. We build APIs and data models around enforceable business rules, clear authorization and reliable state changes.
Python FastAPI backend development, PostgreSQL data modeling, REST APIs, secure authorization, SQLAlchemy, Alembic migrations and production business workflows.
Discuss this serviceModel the business entities, authorization boundaries and failure cases.
Implement explicit schemas, migrations, API contracts and tests.
Validate transaction and callback behavior before production release.
These products and client systems illustrate relevant engineering work. Each case study identifies the delivery context and supported platforms.
Our products
Rent collection and reconciliation software for landlords and property managers. RentPayor connects iOS and Android apps with a web management dashboard for landlords and property managers. It handles properties, leases, rent invoicing, M-Pesa collections, partial payments, automatic reconciliation, receipts, credits and reporting.
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Hospital management information system connecting patient registration, OPD, emergency, inpatient care, orders, referrals, theatre, billing, ambulance, mortuary, duty coverage, patient movement, documents, and facility operations. It includes facility-bound Tuma M-Pesa patient billing and reconciliation, alongside SaaS subscription billing infrastructure.
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School-fee billing and collection software with an Android parent experience and web administration dashboards for schools. Manages students, guardians, term invoicing, M-Pesa payments, receipts, balances and reconciliation.
Read case studyClient work
Cargo and logistics operations platform spanning mobile field workflows and back-office administration. Macsim handles loads, reservations, driver assignments, trip tracking, documents, notifications, fleet operations and finance, with a guarded M-Pesa/Daraja flow for funding a collection-account ledger and paying drivers in full or partial load installments.
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Talk directly with the engineer responsible for your project. Joeltech Geek Systems works with businesses and founders in Kenya and across the world.