Antonin Crestois
Solutions Architect · CRM Architecture, Integrations & AI
Singapore
About
Customer-facing Solutions Architect with 5+ years at HubSpot leading technical integrations (API design, data sync, auth flows, and webhook-driven automation) from discovery through POC for enterprise accounts.
Experience
Associate Solutions Architect
Nov 2025 – Present
Enterprise SaaS · Singapore
- Design HubSpot solutions spanning custom object data models, REST API integrations, workflow automation, reporting, and AI-enabled processes for a portfolio of ~30 enterprise and upmarket accounts.
- Lead discovery workshops that clarify priority problems, map where the current setup breaks, and deliver phased implementation roadmaps.
- Designed and delivered an automation solution saving the customer ~4,800 hours and ~A$135K annually, and turning a churn-risk account into one of the region's heaviest platform adopters within two months.
- Drove AI adoption for a strategic upmarket customer, growing usage from 14% to 955% of baseline allocation within one month and unlocking a 50x credit expansion; the solution sourced new pipeline worth ~3,500x return on credit spend.
- Work with Customer Success and Sales on strategic accounts to stabilise adoption and expand platform use through better lifecycle visibility, segmentation, and reporting.
Recognition
HubSpotlight H1 Winner — 2026 — Named HubSpotlight H1 winner for higher platform usage across the portfolio.
2026 Solutions Top Performer (JAPAC) — Named JAPAC/global Top Performer three months running (March, April, May 2026) for customer engagement volume and customer value.
Senior Product Expert
May 2024 – Oct 2025
Enterprise SaaS · Singapore
- Root-caused enterprise API integration failures by tracing errors through Amazon Athena SQL log queries, inspecting request/response payloads, and reading platform endpoint source code to isolate faults between customer implementations and platform behavior.
- Wrote Python scripts to execute bulk data remediation via REST API for enterprise accounts, and delivered corrected API call sequences directly to customer engineering teams.
- Served as DRI for enterprise escalations on accounts tied to renewal and expansion revenue, reproducing complex failures in test environments before escalation and cutting Engineering resolution cycles.
- Built quantified business cases from customer feedback, usage data, and support insights that informed product roadmap prioritisation.
Recognition
HubSpotlight Annual Global Winner — 2024 — Recognized as the year's top PE performer with 1,673 issues triaged across 2024.
HubSpotlight Bi-Monthly, Most Jiras Triaged — Jul+Aug and Nov+Dec 2024.
Product Expert
Jul 2022 – May 2024
Enterprise SaaS · Singapore
- Debugged HubSpot Data Sync pipeline failures at the log level via CLI, tracing initial and incremental sync jobs through record matching, field mappings, and write actions to isolate where the engine stalled or errored.
- Resolved rate limiting, pagination, and bulk transfer failures on customer API integrations by diagnosing the customer's implementation, not only platform behavior.
- Resolved complex CRM architecture, integration, API, and automation issues for enterprise customers.
- Worked with Support and Engineering to accelerate high-impact platform issues, across the highest global issue volume in 2024 (1,673 issues).
- Built business cases for product improvements from customer feature requests and support data, with quantified ROI.
Senior Customer Support Specialist
Apr 2022 – Jul 2022
Enterprise SaaS · Singapore
- Exceeded CSAT and productivity targets while supporting high-volume enterprise customer interactions.
- Resolved complex technical issues through root-cause analysis.
Customer Support Specialist
Mar 2021 – Apr 2022
Enterprise SaaS · Singapore
- Designed and delivered technical onboarding training in HTML, CSS, HubL, and JavaScript, accelerating ramp-up for ~20 new technical hires.
- Identified expansion opportunities during frontline interactions, sourcing sales-qualified leads for Sales follow-up.
- Exceeded KPIs across volume and quality, earning Growth Champ, Numbers Superstar, and Spotlight awards.
Digitize Intern
May 2019 – Dec 2019
Media Agency · Singapore
- Managed SEM and paid social campaigns for Dyson across JAPAC markets.
- Automated monthly reporting across 13 markets, cutting reporting time by 50%.
- Delivered budget pacing and weekly performance reports with optimisation recommendations.
Recognition
HubSpot Fellows (2025)
Selected for HubSpot's Fellows program.
JAPAC Monthly Top Performer
Won 10 of 12 months from June 2024 to May 2025 for highest issue volume triaged in JAPAC.
Projects
RAG Search Endpoint for Equipment Documentation
Python · FastAPI · Docling · ChromaDB · MiniLM
Retrieval API over a public-domain technical manual (Docling parsing, MiniLM/Chroma retrieval) that returns source-grounded excerpts for HubSpot Customer Agent actions.
Next.js App Router · Tailwind · MDX · shadcn/ui
Personal site for resume, project work, and technical articles.
Education
Singapore Management University
Bachelor of Business Management (Marketing)
Singapore · Aug 2016 – May 2020
Stack — Python, JavaScript/TypeScript, SQL, React, Next.js, REST APIs, HTML/CSS/HubL
Platforms — HubSpot CRM, Salesforce, Shopify, Stripe, Snowflake, Supabase, AWS (S3, Athena)
Tools — GitHub, Postman, Jira, Grafana, Google Analytics, Cursor, Codex CLI, Glean