Software Engineer-PMTS

job summary: You will own the architecture and design of the platform behind Slack’s voice agent - a native mobile voice/AI assistant experience inside the Slack mobile ecosystem. This is production work, not prototyping: your services, APIs, and pipelines must meet the bar of Slack’s production codebase - modular, tested, linted, accessible, and performant at Slack’s scale (tens of millions of users).

Slack is an extremely design-driven organization. Every hire, engineering included, must have demonstrable design sensibility and experience working within (or adjacent to) a mature design system. As the principal engineer on the project, you set the technical standard that our iOS and Android client engineers build against.

location: Telecommute job type: Contract salary: $178.29 - 188.29 per hour work hours: 8am to 5pm education: Bachelors

responsibilities:

• Own end-to-end architecture and technical design for the voice agent platform: service decomposition, API contracts, data models, failure modes, and latency/capacity budgets for real-time conversational experiences.
• Design, build, and operate the RESTful web services that power the voice agent - voice capture/playback backends, streaming agent responses, session state, and deep integration with Slack’s mobile apps - and integrate with (and help modernize) existing SOAP-based enterprise web services in the CIO organization.
• Architect real-time communication layers (WebSockets / streaming APIs) for low-latency voice and agent responses: connection management, backpressure, reconnection, and graceful degradation.
• Define the client-service contracts that iOS and Android engineers implement against; review client integration code for architectural soundness.
• Own CI/CD and build infrastructure: Jenkins pipelines (declarative pipelines, shared libraries), Maven builds and artifact management, quality gates, feature flags, and staged rollouts.
• Lead design reviews and code reviews to Slack’s standards; author architecture decision records; mentor senior engineers on the team.
• Collaborate daily with design and product - ensuring voice interaction states (listening / thinking / speaking / error / interruption) are technically realized to spec, not approximately.

qualifications: **Must-have

10+ years of software engineering experience, operating at principal/architect level on large-scale distributed systems - a demonstrated track record of architecture and design ownership, not just implementation.

Expert-level REST API design (versioning, pagination, error models, idempotency, authN/authZ) and working fluency with SOAP/WSDL enterprise web services, including migrating or wrapping SOAP services behind modern REST interfaces.

Production experience with real-time systems: WebSockets, streaming APIs, low-latency backends; voice/audio streaming experience is a strong plus.

Deep JVM services background (Java and/or Kotlin) with expert-level Maven (multi-module builds, dependency management, plugin configuration) and Jenkins (pipeline-as-code, shared libraries, scaling build infrastructure).

Experience building and operating services consumed by mobile clients - you understand what iOS/Android teams need from an API contract.

Shipped and maintained systems at 100K+ MAU minimum; 1M+ MAU strongly preferred - with the observability, incident discipline, and phased-release experience that scale demands.

Rigorous testing culture: unit, integration, and contract testing embedded in CI; Git-based code review culture.

Design sensibility: experience working within or adjacent to a mature design system at a design-driven company.

**Nice-to-have

Prior work at a company with a strong, recognized design language - e.g., Apple, Airbnb, Duolingo, Linear, Figma, Notion, Stripe, Cash App/Block, Headspace, Robinhood, Vercel.

Voice/conversational AI product experience (e.g., OpenAI, , Replika, Siri/Alexa teams): ASR/TTS integration, LLM streaming backends, token-streaming architectures, WebRTC.

Hands-on familiarity with Swift/iOS or Kotlin/Android - enough to review client-side integration with empathy and precision.

Experience in enterprise/CIO-organization environments: security, compliance, and governance requirements for internal-facing platforms.

Accessibility at production depth (voice experiences must be accessible by default).

skills: Alexa,Maven,iOS,APIs,API,audio streaming,code review,streaming,large-scale distributed systems,Figma,Git,Java,JVM,Jenkins,Kotlin,LLM,versioning,Notion,Vercel,pagination,real-time systems,REST API design,SOAP services,SOAP,Siri,software engineering,Stripe,AI assistant,web services,WSDL,WebRTC,WebSockets,empathy,architecture,client-side,prototyping,dependency management,design system,design language,governance,infrastructure,Rigorous testing,security,technical standard

Equal Opportunity Employer: Race, Color, Religion, Sex, Sexual Orientation, Gender Identity, National Origin, Age, Genetic Information, Disability, Protected Veteran Status, or any other legally protected group status.

At Randstad Digital, we welcome people of all abilities and want to ensure that our hiring and interview process meets the needs of all applicants. If you require a reasonable accommodation to make your application or interview experience a great one, please contact HRsupport@randstadusa.com.

Pay offered to a successful candidate will be based on several factors including the candidate’s education, work experience, work location, specific job duties, certifications, etc. In addition, Randstad Digital offers a comprehensive benefits package, including: medical, prescription, dental, vision, AD&D, and life insurance offerings, short-term disability, and a 401K plan (all benefits are based on eligibility).

This posting is open for thirty (30) days.

It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.

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• Own end-to-end architecture and technical design for the voice agent platform: service decomposition, API contracts, data models, failure modes, and latency/capacity budgets for real-time conversational experiences.
• Design, build, and operate the RESTful web services that power the voice agent - voice capture/playback backends, streaming agent responses, session state, and deep integration with Slack’s mobile apps - and integrate with (and help modernize) existing SOAP-based enterprise web services in the CIO organization.
• Architect real-time communication layers (WebSockets / streaming APIs) for low-latency voice and agent responses: connection management, backpressure, reconnection, and graceful degradation.
• Define the client-service contracts that iOS and Android engineers implement against; review client integration code for architectural soundness.
• Own CI/CD and build infrastructure: Jenkins pipelines (declarative pipelines, shared libraries), Maven builds and artifact management, quality gates, feature flags, and staged rollouts.
• Lead design reviews and code reviews to Slack’s standards; author architecture decision records; mentor senior engineers on the team.
• Collaborate daily with design and product - ensuring voice interaction states (listening / thinking / speaking / error / interruption) are technically realized to spec, not approximately.

Alexa,Maven,iOS,APIs,API,audio streaming,code review,streaming,large-scale distributed systems,Figma,Git,Java,JVM,Jenkins,Kotlin,LLM,versioning,Notion,Vercel,pagination,real-time systems,REST API design,SOAP services,SOAP,Siri,software engineering,Stripe,AI assistant,web services,WSDL,WebRTC,WebSockets,empathy,architecture,client-side,prototyping,dependency management,design system,design language,governance,infrastructure,Rigorous testing,security,technical standard