Financial services / Employment contribution
Keep bank connections working behind the products that depend on them.
Backend engineering at Brankas on open-finance infrastructure: bank and e-wallet connectors across Southeast Asia, then two regulated open-banking platforms with FAPI-grade OAuth2, consent management and partner portals.
- Project
- Open banking integrations
- My role
- Software engineer
- Scope
- Bank connectors, regulated open-banking platforms, consent management and partner portals
- Built with
- Go, gRPC, PostgreSQL, Kubernetes, OAuth2 / FAPI
- Period
- 2022–present · employment period
- Project status
- Ongoing employment
Engineering focus
Bank connectors that outlive the bank’s changes
Connectors for banks and e-wallets across four Southeast Asian countries, through official APIs and bank web channels, including a full rebuild when one bank changed its API. Maintained as each portal, OTP flow and error surface changed.
Regulated open-banking platforms end to end
Core-banking integration, consent management, maker-checker role workflows and partner onboarding for two national open-banking programmes, shipped from gRPC contract through service, storage and portal.
FAPI-grade security and spec conformance
OAuth2 with mTLS, PAR, signed request objects, JWS and JWE payloads. Owner of the spec-conformance suite, with the rule that a failing spec test fixes the implementation, not the test.
Work carried out by Jufianto Henri as an employee of Brankas, with its product and engineering teams. This is not a Sevtee client engagement. Partner banks, customers, internal systems, and metrics are confidential and are not disclosed; the diagram is a simplified overview.
Employment dates from Jufianto’s professional profile. This is the role period, not a project timeline. Current role. The case study describes the kind of work involved. Clients, partner banks, internal systems and metrics are not disclosed.
Integrations that other products stand on
Open banking products depend on connections to many banks, each with its own interface, rules, and failure behaviour. When a connection degrades, the products built on top of it feel it immediately. The engineering job is to keep those connections dependable while the banks, the regulations, and the products keep changing.
Since 2022 I have worked on that layer at Brankas, an open-finance infrastructure company in Southeast Asia.
What the work involves
The work has come in three chapters. The first was bank connectivity: connectors for banks and e-wallets across four Southeast Asian countries, built against an official API where the bank offers one and against the bank’s own web channel where it does not, and kept working as each bank changed its login, OTP flow, or error responses. One connector I owned for three years was rebuilt in full when the bank changed its API underneath it.
The second was a regulated open-banking platform for a bank in the Middle East: integrating the bank’s core-banking middleware, building consent management and partner onboarding, moving user and role management into its own service, and closing the findings of a formal penetration test across the platform.
The third, and current, is a national Open Finance Platform in Southeast Asia built to the FAPI security profile: OAuth2 with mTLS, signed request objects, and JWS and JWE on every payload. I own the specification-conformance test suite and ship portal features end to end, from the gRPC contract through service, storage, and portal, with acceptance tests at the service boundary.
This is team work inside an employer’s platform. My contribution is backend engineering within those teams, not ownership of the whole product.
Why it matters for a client project
Payment and banking integrations come up regularly in client work: connecting an application to a payment service, reconciling transactions, or handling an external API that behaves differently from its documentation. So does the security side: OAuth2 done properly, signed and encrypted payloads, and permission models that hold up under review. This experience is the background for the integration work Sevtee offers. Bank names, partner details, internal architecture, and performance figures are confidential and are not part of this case study.