Backend Engineer, Payments and Billing

Location: Pune, India (in-person) Experience: 3 to 7 years Reports to: Founder and CEO Employment type: Full time

Mandate

This role builds and owns the system through which all revenue flows. It covers payment gateway integration, subscription and metered billing, the credit ledger, invoicing, reconciliation, and partner payouts. Correctness is the primary standard. A billing system that is fast and wrong has no value.

Core responsibilities

Design and build an internal payments abstraction that sits above multiple payment service providers, so that provider selection, routing, and failover are configuration decisions rather than code changes. The initial integration scope covers one global provider and one India-domiciled provider.

Implement the full subscription lifecycle: creation, upgrade, downgrade, mid-cycle proration, pause, cancellation, reactivation, trial conversion, and involuntary churn handling through dunning and retry sequencing.

Build the usage metering and rating pipeline. This includes reliable event ingestion, deduplication, late and out-of-order event handling, aggregation, rate card application, and the production of an auditable charge record for every billable unit consumed.

Implement a double-entry credit and wallet ledger with immutable transaction history, supporting purchased credits, promotional credits, incentive-issued credits, differing expiry rules, and a defined consumption precedence order.

Handle recurring collection through card tokenisation and network tokens, mandate-based instruments including automated bank debit and UPI-based recurring authorisation, and authentication flows including 3DS and strong customer authentication where applicable.

Build webhook infrastructure to a production reliability standard: signature verification, idempotency keys, safe replay, out-of-order tolerance, dead letter handling,



and reconciliation of any state divergence between the internal system and the provider.

Implement multi-currency support, including presentment and settlement currency handling, foreign exchange treatment, and country-specific payment method coverage.

Integrate tax computation and compliant invoice generation across the relevant jurisdictions, covering domestic indirect tax, European value added tax, and United States sales tax obligations.

Build daily automated reconciliation against provider settlement files, with break detection, alerting, and an investigation workflow. Reconciliation is a first-class deliverable, not an afterthought.

Implement refunds, partial refunds, chargeback and dispute handling, and the evidence submission workflow.

Build attribution and payout infrastructure for partner and referral programs, including event attribution, commission calculation, holding and clearing periods, clawback processing, payout batching, and statutory deduction at source.

Implement entitlement enforcement and real-time usage limits, including hard stops, soft warnings, and concurrency-bound quota checks that must resolve within tight latency budgets.

Own observability for the revenue path: authorisation success rates by provider and method, mandate failure rates, involuntary churn attribution, webhook lag, and ledger integrity checks, with alerting configured against each.

Maintain scope discipline on cardholder data so that the platform remains within the lightest applicable compliance boundary, and ensure personal data handling meets applicable data protection obligations.





Required qualifications

Three or more years building backend systems, including direct ownership of payment or billing functionality on a live product processing real money. Prototype or side-project payments experience does not meet this bar.

Direct integration experience with at least one major payment service provider, covering subscriptions, webhooks, and the failure modes that appear only in production.

Demonstrated ledger design experience, with a clear understanding of why financial state must be append-only and how balances are derived rather than stored mutably.

Proven handling of idempotency, exactly-once processing semantics, and distributed state consistency in an event-driven system.

Practical reconciliation experience against settlement data, including the operational reality of investigating and resolving breaks.

Strong proficiency in a contemporary backend language such as TypeScript, Python, or Go, with production experience in PostgreSQL, Redis, and message queue infrastructure.

Ability to reason precisely about money, rounding, currency minor units, and floating point hazards, and to explain why decimal handling is not an implementation detail.

Preferred qualifications

Experience with both an international payment provider and an India-domiciled provider, and familiarity with the differences in mandate handling, tokenisation requirements, and settlement behaviour between them.

Prior work with dedicated metering or billing infrastructure platforms.

Background in telecom rating, call detail record processing, or another high-volume usage-based charging setting.

Experience with automated tax computation services and with fraud and risk tooling on the payment path.

Exposure to marketplace or split-settlement payout architectures.

Pay: From ₹30,000.00 per month

Benefits:

- Paid sick time

Work Location: In person

📌 Backend Engineer, Payments and Billing (Pune)
🏢 Blessing SoftTech
📍 Pune