Workflow Developer & Tester

Webbing

Serbia remote Posted May 13, 2026

Description

Description

Implement Temporal workflow activities in Go: HSS adapter, PCRF adapter, Inventory update.

Build and validate unit tests for all workflow activities from day one.

Build the Inventory Management Database: tables, indexes, partitioning for 30M records.

Build bulk import tooling: CSV → ICCID/IMSI/MSISDN range ingestion from vendor.

Implement REST API endpoints for Inventory DB (allocate, reserve, release, query SIM records).

Write integration tests: workflow → mock NE → database assertions.

Support Sr. Developer on all workflow development tasks — pair programming expected.

End-to-end test suite: full provisioning flow from SIM activation to order closed.

Load and stress testing: simulate peak TPS provisioning against all systems.

Test automation: CI pipeline integration for all workflow and API tests.

HSS sync integration: IMSI allocation state reflected in HSS (mock → real NE).

MNP (number portability) hooks in Inventory DB.

UAT support: reproduce bugs, write regression tests, validate fixes.

Requirements
Must Have

2–4 years backend software development in production environments.

Go or Java — primary development language for this role is Go.

Java accepted if strong fundamentals and willing to work in Go (we will support the transition).

REST API development — building APIs consumed by other services and tested by automated suites.

PostgreSQL — table design, indexes, writing queries, understanding query plans .

Unit and integration testing — writing tests is a first-class responsibility, not an afterthought.

Git — branching, pull requests, code review participation.

Experience with event-driven architectures using RabbitMQ, Kafka, or Redis Pub/Sub.

Basic Kubernetes knowledge — understanding how your workloads are deployed.

Ability to work under technical direction of a senior lead and execute quickly.

Fluent English.

Strong Advantage

* Any workflow engine experience: Temporal, Camunda, Apache Airflow, AWS Step Functions.

* Telecom or BSS/OSS background — understanding of SIM lifecycle, provisioning, activation.

* Test framework experience: Go testing, Testify, mock frameworks.

* Load testing tools: k6, Locust, JMeter — running and interpreting results.

* Docker — building and running containerised services.

* Experience with event-sourced or append-only database patterns.

Nice to Have

Temporal.io SDK experience — even personal/side project counts.

Python — useful for scripting, test tooling, data processing.

Prometheus — understanding how to instrument code with metrics.

Telecom protocol familiarity: Diameter, SS7, SMPP.

About Webbing
Founded in early 2010, Webbing is a global data MVNO that delivers enterprise grade, global connectivity and IoT services across more than 200 countries and 600+ mobile carriers' networks. Webbing's secured network delivers network protection and web content intelligence.

Enterprise customers can manage, monitor, and optimize data usage in real-time with Webbing's powerful software platform. Gain visibility by application type and have the power to white list applications and limit non-business applications with the click of a button, saving money and improving compliance.

What we offer

Fully remote

An exciting and challenging greenfield platform with great skill and knowledge development opportunities.

The opportunity to join a team of highly professional specialists in an international environment.

The opportunity for professional development within a reputable international innovative and growing company.