‍For PubNub, the last 5% of commitment coverage was the hardest to close, and the most valuable. Archera closed it without adding headcount or engineering work.

PubNub is a real-time communication platform powering chat, presence, and data streaming for applications across gaming, IoT, and financial services. That scale means PubNub's AWS usage is a mix of steady, predictable baseline traffic and bursty, hard-to-forecast spikes.

By the time PubNub started working with Archera, its finance team had already reached 95% AWS commitment coverage, a level most companies treat as the finish line. But the remaining 5% was the volatile, unpredictable slice of workload that wouldn't fit neatly into a 1- or 3-year Reserved Instance or Savings Plan.

That last stretch is where Archera came in.

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The Challenge: The Last Few Points of Coverage Resist Long-Term Commitments

Once a company is already at 95% commitment coverage, the remaining gap is the hardest to close. It's made up of the volatile, unpredictable workload that won't fit a 1- or 3-year lock, and the risk of getting it wrong cuts both ways:

• Volatile, bursty usage patterns tied to traffic spikes and scaling events that don't repeat predictably
• Long-term Reserved Instances and Savings Plans require locking into an instance mix months or years in advance
• Committing too aggressively risks eating a 3-year payment on capacity that's no longer needed, with no clean way to unwind it

"We've had previous bad experiences where, despite the best forecast and alignment across our CEO, our CFO, myself, and engineering directors, we finally came down to a multimillion-dollar, one- to three-year commit — felt so good about it. And then our engineering team six months later decided to rebuild one of our services and become more performant. Good, but darn. Then you have to watch that unused commitment every single month." — James Hamilton, VP Operations & Controller at PubNub

As a result, the last three to five points of coverage are the ones most finance teams leave on the tablebecause the tools available were all-or-nothing.

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The Solution: A Three-Layer Commitment Portfolio Built for Bursty Workloads

Working with Archera meant rethinking commitments as a spectrum rather than a single, high-stakes decision.

"This was a big mind shift for us. We needed to think about how our commitments could be broken up into a spectrum of purchases versus a single one-time buy." — James Hamilton, VP Operations & Controller at PubNub

Archera restructured PubNub's commitment portfolio into three layers, each matched to a different type of usage:

• 3-year native commitments (73% of spend): the predictable baseline workload, already well covered with the deepest available discount
• 1-year native commitments (5% of spend): medium-horizon bridge coverage
• Archera 30-day Insured Commitments (22% of spend): the volatile, unpredictable layer that had historically been impossible to lock without taking on multi-year term risk

Instead of manually forecasting usage and negotiating longer terms, PubNub now relies on Archera to:

• Ingest PubNub's AWS cost and usage report daily and model the optimal commitment shape by account, region, and instance family
• Autonomously purchase real AWS RIs and Savings Plans at a 30-day term when a coverage gap is identified with high confidence the same discount, on a much shorter horizon
• Refund the unused portion of any 30-day commitment that goes underutilized, so PubNub keeps the discount while Archera carries the term risk

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The Outcome: $4.21M in Net Savings, Zero Infrastructure Changes

By closing the final coverage gap with Archera, PubNub achieved meaningful savings without adding operational overhead.

Key outcomes include:

• $4.21M in net savings over 18 months at a 41.3% blended effective discount
• Commitment coverage raised from 95% to 98%+
• Zero infrastructure changes, zero engineering involvement, and zero procurement cycles required
• The full program managed by a single finance lead, with optimization running continuously in the background

The value of that last layer showed up clearly during a real usage surge. In 2025, a customer-driven spike pushed PubNub's daily EC2 and Fargate spend 46% above baseline. Archera's 30-day Insured Commitments detected the gap and restored coverage in under 30 days, holding $245K in net savings during the spike month with no on-demand bleed reaching the bill.

When the surge subsided, the commitments rolled off automatically. No 3-year hangover, no procurement cycle, and no engineering work on PubNub's side.

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What's Next: Sustaining Coverage as Usage Keeps Shifting

As PubNub's usage patterns continue to evolve, Archera remains the layer that keeps commitment coverage above 98% without requiring PubNub to predict what comes next.

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See PubNub tell this story live at FinOps X