It's really easy to setup your own cache module in @elixirlang that uses ETS and supports proactive warming. Proactive warming prevents slow cache misses. (Which show up as spikes in latency graphs/ruin your p95.) Also uses a neat trick, `:timer.apply_after`: Make a struct with your cache config: The `cache_name` becomes the ETS bag/key-value store for all cache entries. `warm_after` specifies when the warming should kick off – notice it's conservatively set 30s under the TTL. `warmer` indicates the warming function to call in order to warm the cache after `warm_after`. The `cache_name` becomes the ETS bag/key-value store for all cache entries. `warm_after` specifies when the warming should kick off – notice it's conservatively set 30s under the TTL. `warmer` indicates the warming function to call in order to warm the cache after `warm_after`. We should never hit the TTL thanks to warming, but I like the backstop. Implement a public `lookup` function. Here's what it will look like calling it – it accepts a callback that it invokes on cache miss: When implementing `EtsCache.lookup/3`, respect `expires_at`: You may consider logging if you have to fall back to `expires_at`, likely means your warming took too long or failed! In the `EtsCache.insert/3` function, you can use `:timer.apply_after` to achieve warming: Note, you might consider adding some jitter to `config.warm_after`. Otherwise, on system boot, you might have a LOT of timers that always fire at the same time. Finally, implement your warming function anywhere. It will simply insert into the cache: ``` # Outside EtsCache, in the module that's using it def warm_load_cached(resource_id) do resource = load_resource!(resource_id) EtsCache.insert(resource_id, spec, @cache_config) end ```

What makes @elixirlang great for startups? The biggest problem most startups face is trying to find product/market fit. The key to discovering product/market fit is rapid iteration. You need to build, measure, and adapt quickly based on customer feedback. Ruby on Rails understood this well, and bootstrapped tons of really big companies. The top four YC companies by value are Airbnb, Stripe, Coinbase, and DoorDash – all originally Rails shops. [1] Rails was and is really good. It's surprising that other languages and frameworks still haven't caught up. I feel for younger startup teams that don't know how good we had it. There's one ecosystem that doesn't have a Rails-shaped hole, though: Elixir. Elixir is a great choice for a team that wants to move fast. Here's why: