Tillster

Senior Software Engineer – Back End

Tillster
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2 months ago

Base Salary

$150k - $165k/yr

Responsibilities

  • Own the kiosk payment domain, including authorization, capture, voids, refunds, reversals, settlement, and reconciliation.
  • Re-architect the existing platform into a modular, pluggable payment SDK with versioning, compatibility, capability negotiation, dependency isolation, configuration, and secret management.
  • Design a common terminal abstraction across integrated, semi-integrated, cloud, REST, and cash-device processors.
  • Build integration testing, simulation, certification, and regression-testing harnesses for internal and external integrations.
  • Establish platform patterns for idempotency, transaction recovery, reversal, timeouts, health monitoring, concurrency, and reconciliation.
  • Design PCI-DSS scope minimization using tokenization, P2PE, TLS/mTLS, and secure certificate and key handling.
  • Implement terminal integrations from byte-level protocols through the high-level PayTerminal API.
  • Work with RS-232, USB-serial, USB, terminal SDKs, processor APIs, webhooks, retries, polling, and reconciliation.
  • Debug live hardware using protocol traces, terminal logs, packet captures, and vendor certification cycles.
  • Lead architecture and design reviews, set technical direction, and mentor engineers.

Requirements

  • 6+ years of backend engineering experience with strong Java, object-oriented programming, and distributed-systems design experience.
  • Experience designing extensible plugin, SPI, or SDK architectures, including ServiceLoader, OSGi, Spring plugin models, or public SDKs.
  • Hands-on serial or USB communication and binary protocol implementation experience, including TLV, BCD, bitmaps, length-prefixed fields, and state machines.
  • Direct payment-terminal or POS integration experience with providers such as Verifone, Ingenico, Adyen, Shift4, FreedomPay, SIX, Nepting, SiTef, Redsys, Worldpay, or comparable platforms.
  • Understanding of card transaction lifecycles, PCI-DSS boundaries, tokenization, and TLS/mTLS in production.
  • Demonstrated technical leadership through design leadership, standards-setting, and mentoring.
  • EMV, ISO 8583, ZVT, or OPI experience is a strong plus.
  • Experience with cash automation, recyclers, end-of-day and reconciliation tooling, regional acquiring, multi-currency payments, loyalty, stored value, gift, Apple Pay, Google Pay, vendor certification, 3-D Secure, SCA, or fraud and risk tooling is preferred.

Benefits

  • Hybrid role requiring the employee to be based in San Diego, California; local candidates only.
  • Medical, dental, vision, FSA, healthcare and dependent-care reimbursement programs, EAP, and Optum Care counseling services for eligible full-time employees and dependents.
  • Ten paid holidays per calendar year.
  • 15 days of PTO during the first 12 months of continuous service and 22 days in subsequent years; eligible part-time employees receive prorated PTO.
  • 401(k) plan eligibility beginning on the employment start date.
  • College tuition and education assistance, Udemy courses, and ongoing learning and development opportunities.
  • No visa sponsorship; principals only and no agencies or calls.

Tech Stack

JavaMavenSOAP

Categories

Tillster

About Tillster

201-500 employees
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